Structure and cell functions Flashcards
What is a prokaryote?
A cell lacking membrane bound organelles with loose, looped DNA
What is a eukaryote?
A cell with membrane bound organelles and structured DNA
What is a nucleoid?
Where DNA is stored in prokaryotes
What is a tonoplast?
A partially permeable membrane surrounding the vacuole
What is a centriole?
Tubes of microfilaments forming spindle like tubes during mitosis
What are the three parts of cell theory?
- All living organisms are composed of cells
- The cell is the most basic unit of structure and cells organise and form organisms
- Cells cannot form spontaneously, all cells arise from other cells
Prokaryotes
What is a plasmid?
What are they responsible for?
Plasmids are small circular loops of DNA
They are responsible for antibiotic resistance
Prokaryotes
What are 70s (Svedberg) ribosomes?
Ribosomes are responsible for making proteins
Prokaryotes
What is a nucleoid?
A nucleoid is like a nucleus, but lacks an enclosed membrane. Dna is a single loop.
Prokaryotes
Features of the cell wall?
A cell wall made out of peptidoglycan supporting and protecting the cell
Prokaryotes
What is a capsule?
A ‘slime’ that protects the cell and ensures it doesn’t dry out
Eukaryotes
What is a vesicle?
Sacs filled with substances requiring transport around or out of cells
Eukaryotes
What are lysosomes?
Sacs filled with hydrolytic enzymes that break down cellular waste
Eukaryotes
What are 80s ribosomes?
The site of protein synthesis located in the cytoplasm and the rough endoplasmic reticulum
Eukaryotes
What is the nucleus?
Stores genetic material and has a nucleolus which makes RNA and ribosomes
Eukaryotes
What is a plasma membrane?
A plasma membrane acts as a barrier and allows certain substances to cross into the cell
Eukaryotes
What is the golgi apparatus?
Receives, modifies and packages proteins
Eukaryotes
What is the rough endoplasmic reticulum?
The site of protein synthesis and transport to the golgi apparatus
Eukaryotes
What is the smooth endoplasmic reticulum?
The site of lipid and carbs synthesis and transport
Eukaryotes
What is the cytoplasm?
Containing chemicals
Eukaryotes
What is the mitochondria?
Site of cellular respiration - energy is released
Eukaryotes
What are centrioles?
Produce spindle fibres for cell division
Plant cell addition
What is a vacuole?
Membrane bound sac which maintains pressure and stores cell sap
Plant cell addition
What are chloroplasts?
Site of photosynthesis
Plant cell addition
What are amyloplasts?
Membrane bound sacs which synthesises and stores starch granules
Plant cell addition
What is a plasmodesmata?
Strands of membrane that pass between cells for transport and communication
Plant cell addition
What is a cell wall?
Protects and supports the cell, made of cellulose
Plant cell addition
What are pits?
Pores between cells allowing water to enter and leave cells
What are the 6 steps to gram staining?
- Bacteria culture smeared onto slide
- Heat applied to fix bacteria
- Crystal violet stain
- Iodine to trap Crystal violet
- Alcohol to rinse excess stain
- Counterstain eg Safranin to stain unstained bacteria
What colour does gram positive bacteria produce?
Purple
What colour does gram negative bacteria produce?
Pink/red
Gram positive bacteria have a t_____ p_______ c_____ w_____
thick peptidoglycan cell wall
Gram negative bacteria have a f_____ l_____
fatty later
What bacteria isn’t treatable with antibiotics?
Gram negative
